Thanks to this list and its good members, I got support contact easily,along with lots of helpful information. It seems my issue is solved for now. OK MS support. I have few users, who are paid customers of MS. Possibly, they also lodged the issue with MS. But it is still bad for a reputed organization to silently discard the messages. I guess there is a problem of tuning with there mail firewall.
Following is the reply from MS, which explains noting to me technically. Any way my relay is a low traffic sender. ------------------- Our investigation has determined that there are no active blocks against these IP(s); however, some messages were filtered. We have confirmed that these IP(s) are eligible for conditional mitigation, but may be subject to low daily email limits until they have established a good reputation. Please note that this mitigation does not guarantee that your mail will be delivered to a user's inbox. --------------------------- Sincerely, Soumitri Mishra, IITK On 07/01/18 4:12 AM, Yuval Levy wrote:
TL;DR: IF YOU ARE STILL EXPERIENCING DELIVERABILITY ISSUES, CONTACT OUTLOOK.COM DELIVERABILITY SUPPORT: <http://go.microsoft.com/fwlink/?LinkID=614866>
